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Twelve years to safeguard the planet

IPCC warns world only has limited time to keep global temperature rises to 1.5C

Scientists from the UN Intergovernmental Panel on Climate Change (IPCC) have sounded a “clarion call” to act on climate change, and put a timeframe on keeping global temperature rises to within 1.5C: 12 years. A figure between 1.5C and 2C was agreed by all 195 countries at landmark climate talks in Paris in 2016, but if global warming reaches the higher number, then a catalogue of disastrous effects await.

The UN body is now warning that time is running out to make the vital and unprecedented changes required to prevent global warming crossing the 1.5C threshold. Climate change is already happening, it says, but 2030 – just 12 years, or 144 months from now – is the point at which risks begin to grow of catastrophic consequences for the environment and for us. If work to address the situation begins then, rather than now, then the effort required to keep rises to 1.5C would be astronomical.

In a report commissioned after Paris and published last week, the IPCC says it is possible for countries to meet the ambitious target set in the French capital, because the technology to do so is already in existence, but swift and far-reaching action must be taken now. Measures would include encouraging citizens to cut down on their meat intake, thereby reducing the number of feed animals in the world; less livestock would mean less harmful greenhouse gases, and would free up more land to grow crops for human consumption.

“It’s a line in the sand and what it says to our species is that this is the moment and we must act now,” said Debra Roberts, who co-chaired the working group on impacts. “This is the largest clarion bell from the science community, and I hope it mobilises people and dents the mood of complacency.”

If the target is missed by just half a percentage point – that is, if temperatures rise to 2C – insects and plants would be likely to lose half their habitat; 99 per cent of corals would die off; the Arctic would be ice-free in summer every 10 years (rather than every century at 1.5C); and extreme weather events would be more likely, leading to food scarcity, flooding, heat-related deaths and forest fires; sea level rises would increase by an extra 10cm, affecting 10 million more people by the end of the century.

The IPCC report sets out four ways in which the 1.5C threshold could be met, using both technology and changes to the way we use land. Carbon pollution needs to be cut by 45 per cent, and hit zero by 2050, and key to each of the four plans is planting more trees. The report makes it clear that deforestation caused by agriculture is destroying vast tracts of forest, which are vital carbon sinks. A study last week also said people should be eating meat less than once a week if climate targets are to be met.

“I hope this can change the world,” said one of the authors, Jiang Kejun, of China’s semi-governmental Energy Research Institute. “Two years ago, even I didn’t believe 1.5C was possible but when I look at the options I have confidence it can be done. I want to use this report to do something big in China.”

Jim Skea, who co-chairs the working group on mitigation added: “We have presented governments with pretty hard choices. We have pointed out the enormous benefits of keeping to 1.5C, and also the unprecedented shift in energy systems and transport that would be needed to achieve that. We show it can be done within laws of physics and chemistry. Then the final tick box is political will. We cannot answer that. Only our audience can – and that is the governments that receive [the report].”